"Plugins" are small programs, that can be added to QGIS.
For example sometimes you are wondering, how you can solve a task in QGIS. At this time you can check, if there is a plugin, that can solve exactly your task in a smart way.
You can find "Plugins" in the top menu (se below):
Click on "Manage and Install Plugins...", and this box will popup:
Here you can see, which "Plugins" are already installed. You can also upgrade "Plugins" or delete or install them again.
In the left panel you see, that you are now on the "Installed" page. Click on "Get More", and the screen now looks as below:
As the text on the right panel says, you can now see all the "Plugins", which are not installed.
You can search for "Plugins" by writing in the "Search" field at the top.
If you want to install a "Plugin", just click on/mark it and click on the button "Install plugin", which will appear.
Then click on "Settings" in the left panel, and you will see this screen picture:
Here you can edit the settings for "Plugins". For example you can tell the system to automatically check for upgrades and to alert you, when upgrades are found.
You are welcome to write comments below. If you have any questions, please post in the forum.